#include<map>
#include<set>
#include<cmath>
#include<vector>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<iostream>
#include<algorithm>
#define rep(i,a,b) for(register int i = (a);i <= (b);++i)
#define per(i,a,b) for(register int i = (a);i >= (b);--i)  
typedef long long ll;
typedef unsigned long long ull;
using std::string;using std::cin;using std::cout;

int t,n,a[111],s[111],m;

int main(){
    std::ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    //freopen("in.in", "r", stdin);
    cin >> t;
    while(t--){
        m = 1;
        rep(i,1,110) a[i] = 0 , s[i] = 1;
        cin >> n;
        rep(i,1,n){
            cin >> a[i];
            m = std::max(m,a[i]);
        }
        rep(i,1,m) cout << 'a';
        cout << "\n";
        rep(i,1,n){
            s[a[i]+1] = !s[a[i]+1];
            rep(i,1,m){
                if(s[i]) cout << 'a';
                else cout << 'b';
            }
            cout << "\n";
        }
    }
    return 0;
}